Syrian troops fired live ammunition and tear gas on tens of thousands of protesters calling for the regime's ouster in several cities around the country Friday, killing at least 10 people, the Local Coordination Committees said.

The protests, which have become a weekly ritual following Friday prayers, came hours after a bomb blast struck a major oil pipeline in western Syria, causing oil to spill into a nearby lake. State television said the explosion was a "terrorist" attack by a group of "saboteurs."

The London-based Syrian Observatory for Human Rights said troops on Friday opened fire in the Mediterranean town of Latakia, killing at least one protester there.

The Local Coordination Committees, which also track anti-government protests, said at least 10 demonstrators were shot dead by security forces in several cities.

Troops beat up protesters in the northwestern coastal town of Banias and fired tear gas in several other locations. There were also marches in the countryside around Damascus despite an intense crackdown there in the past few days.

Opposition groups have dubbed Friday's protests "Your silence is killing us," in an attempt to mobilize sections of the population that have not yet joined the protests and Arab leaders who remain silent about the crackdown in Syria.

Syrian authorities have unleashed a brutal crackdown in an effort to crush the revolt against President Bashar Assad, and activists say more than 1,600 civilians have died since the protests erupted in mid-March. The government blames the unrest on terrorists and foreign extremists, not true reform-seekers.

The pipeline blast was the second incident involving an oil pipeline in a month, and the second time this week that authorities accused saboteurs of striking installations.

The pipeline carries crude from the oil fields in the oil-rich eastern Deir Ezzor to a refinery in Banias, which is the main point of export for Syrian oil. The country's other refinery is in the central city of Homs.

State TV said the blast hit near the western town of Tal Kalakh between Homs and Tartous, near the Tal Hosh dam, and left a 10 meter deep crater. The TV said the "terrorist attack sought to cause oil to leak into the dam's waters in order to damage agricultural crops in the area."

Oil Minister Sifian Allaw said 1,500 barrels of crude oil leaked from the struck pipeline into the water behind the dam. He told The Associated Press that the pumping of oil was transferred to another pipeline without interruption in the flow.

The oil that gushed into the dam's waters caused a large spill, turning parts of the surface to black.

Numeir Makhlouf, chairman of the state-owned Syrian Company for Oil Transport, told state-run SANA news agency that the oil had leaked into a main lake that supplies the vast agricultural western area with irrigation water.

The area of Friday's blast, Tal Kalakh, is an opposition stronghold near the border with Lebanon that was overrun by army tank units, security forces and pro-regime gunmen in May after weeks of protests calling for the president's ouster.

Rights activists say around 35 people died in the deadly crackdown and siege of Tal Kalakh, which is about 50 kilometers from Homs, a hub of anti-government protesters and scene of a brutal government crackdown in recent weeks.

Syria's oil exports are among the main earners of foreign currency for the government, especially now that the uprising has hit the tourism industry. Last year, tourism accounted for roughly 12 percent of GDP and brought in $8 billion in hard currency.

Syria produces about 350,000 barrels of oil per day as well as natural gas.

On July 13, a blast and a fire struck a natural gas pipeline in eastern Syria. Some rights groups said it was an attack but the Oil Ministry denied any explosion and said a fire erupted on a pipeline that was under maintenance.

And last Saturday, authorities said saboteurs tied to the country's uprising caused a passenger train to derail in central Syria, but opposition figures dismissed the accusation.

Activists said security forces killed at least five people overnight.

The Syrian Observatory for Human Rights said security forces shot dead three civilians and wounded 12 in Deir Ezzor province late Thursday, after residents tried to keep the troops away by placing roadblocks and stones in their path.

Last week, Assad had sacked and replaced the governor of Deir Ezzor following massive anti-government demonstrations in the area.

The Observatory also said two people were killed during nighttime raids by security forces in a Damascus suburb, near the town of Zabadani.